Grinding machine



Feb. 21, 1939. s, HMS 2,141,893

GRINDING MACHINE Filed Oct. 4, 1937 4 Sheets-Sheet 1 INVENT OR. FEEDEE/CK 6T HAM BY Wm ATTORNEY.

Feb. 21, 1939. F. s. HAAS 2,147,893

GRINDING MACHINE Filed Oct. 4, 1937 4Sheets-Sheet 2 INVENTOR. FEEDER/(X3 H445 ATTORNEY.

Feb; 21, 1939. S, HMS 2,147,893

GRINDING MACPINE Filed Oct. 4, 1957 4 Sheets-Sheet 3 IN VENTOR. FEEDER/CK 5 H4195 WWW/4v ATTORNEY.

Feb. 21, 1939.

F. S. HAAS GRINDTNG MACHINE Filed Oct. 4, 1937 WT f/////] in 4Shee'ts-Sheec 4 INVENTOR. FEDEE/CK 5 HaAs ATTORNEY.

Patented Feb. 21, 1939 UNITED STATES camnmc mourns Frederick S. Haas,Cincinnati,- Ohio, assignor to Cincinnati Grinders Incorporated,Cincinnati; Ohio, a corporation of Ohio Application October 4,

12 Claim.

ing movements in an extremely simple and efilcient manner.

A further object of the invention is the provision of a controlmechanism which shall include I a lost motion device permitting clampingof the work at the initiation of the control movements and a delayedunclamping or release of the work effective subsequent to initialretraction of the grinding wheel.

A further object of the invention is the provision of a single levercontrol mechanism of this character which will effect successiveclamping and unclamping of the work in predetermined positional sequenceand concurrently with, or independently of, the operation of the feedingmovement for effecting the grinding operation.

An additional object of the present invention is the provision of animproved control mechanism for valve devices for effecting certainmovements of a grinding machine, such as the work clamping and rapidtraverse movements which will actuate the valves in reversed sequenceduring relative approach and retraction of the work and grindingelement.

Other objects and advantages of the present invention should be readilyapparent by reference to the following specification, considered inconjunction with the accompanying drawings forming a part thereof and itis to be understood that any modifications may be made in the exactstructural details there shown and described, within the scope of theappended claims, without departing from or exceeding the spirit of theinvention.

Figure 1 is a plan View of a machine embodying the present invention.

Figure 2 is a sectional view as on the line 2-2 of Figure 1.

Figure 3 is a diagrammatic view of the several controls for the machine.

Figure 4 is an enlarged sectional view illustrating the valves andoperating mechanism therefor as on the line 4-4 of Figure 2.

1931, Serial No. 167,216

Figure 5 is a fragmentary sectional view as on the line 5-50! Figure 2.

Figure 6 is a fragmentary view illustrating the position occupied by thecontrol elements when effecting clamping of the work.

Figure 7 is a view corresponding to Figure 6 showing the positionoccupied by these parts during the grinding operation.

In the drawings in which similar characters of reference are employed todenote similar or corresponding parts: 1

The numeral l0 designates the bed of the machine having ways II for thework chuck carriage I 2 having rotatably mounted thereon the table l3supporting the suitably driven chuck [5 for reception of a work pieceIB. It will be noted that the chuck and its supporting spindle may beangularly adjusted about swivel mounting I! to determine the angle ofpresentation of the periphery of the work to the grinding wheel l8, and,in addition, may be given a bodily adjustment toward and from thegrinding wheel to accommodate different sizes of work or to compensatefor wheel wear as by the lead screw I9 and' pilot wheel 20. Pivotallysupported by the right hand portion of the bed, as viewed in Figures 1and 2, for oscillation about av trunnion axis at 2| is the grindingwheel head 22 support-. ing spindle 23 on which is mounted the wheel I8.

It will be noted that the weight of the wheel head 22 is to the right ofthe pivot, therefore tending to swing the head downward and moving thewheel into retracted position as respects the work piece I6. Twocooperating mechanisms are provided for effecting oscillation of thewheel head in the opposite direction. The first of these comprises acylinder 24 having slideable therethrough the plunger 25 provided withan intermediate piston portion 26. Conduits 21 and 28 coupled withopposite ends of the cylinder permit respectively introduction ofsuitable pressure medium through line 21, to the top of the cylinder,depressing the plunger while the fluid from the lower portion of thecylinder is exhausted through line 28, or alternatively an introductionof pressure into line 28 with concomitant exhaust through line 21causing a positive raising of the plunger.

Contacting the lower end of the plunger 25 is a second plunger 29 havinga roller 30 riding on cam 3| carried by shaft 32 journaled in the bed onsuitable anti-friction bearings and extending to the front of themachine where it is provided with the manually actuable handle 33. Fromthe foregoing it will be seen that cam 3| through the elements 88 and 28takes up the reaction of plunger 25 so that on introduction of pressureinto the upper end of cylinder 24, the cylinder actually will beraisedthe plunger remaining stationary. This raising of the cylindercauses a tilting of the head 22, moving the grinding wheel rapidly inthe direction of the work piece I5.

Additional oscillation of shaft 32 by operation of handle 88 in acounterclockwise direction will oscillate cam 8|, imparting movement asan entirety to the combined plunger 28-25. As the pressure in the upperend of the cylinder is sufficient to maintain piston 28 and plunger 25de pressed or at the bottom of cylinder 24, this action of the camserves to impart a slow or manually controlled infeed movement to thegrinding wheel for effecting the desired stock removal. The extent ofsuch movement may be suitably controlled either by an automatic gagingdevice, a mechanical stop as at 34 for limiting the movement which canbe imparted to lever 83, or by visual size determination anddiscontinuance of the infeed when the work has been reduced to a properpoint. A particular mechanism for accomplishing the latter result hasbeen illustrated in connection with Figures 1 and 3 comprising a gagingmember 85 adapted to contact the work during grinding and cooperatingwith a dial 35 actuable to indicate when the work has been reduced toproper size. This mechanism, as an entirety, is carried by a swingingbracket 81 automatically actuated into and out of position for the gagepoint 35 to contact the work as by a suitable piston cylinder orhydraulic motor, designated as an entirety by the numeral 38.

The particular manner of controlling the cyclic sequential operation ofthese various elements will probably best be understood by reference toFigures 3 and 4. While there has been illustrated what, up to thepresent time, has been found to be the most efficient satisfactoryembodiment in that two independent sources of pressure fluid foractuation of the parts are employed, it is to be understood that ifdesired these could be combined.

As there illustrated, use is made of a sump 40 from which suitablehydraulic medium is drawn by pump 4| and discharged into pressure line42 having one branch leading to the control valve casing 49 and a secondbranch 44 extending to the valve casing 45. With the machine in the idleor non-grinding position, as there shown, conduit 44 is coupled by port45 and valve spool 41 to conduit 28 leading to the lower end of cylinder24 so that plunger 25 is in raised position. At the same time, 42 iscoupled with pressure groove 48 of valve casing 49, and thence, in theposition of the parts shown, through resistance 58 to lines and 52, line5| being at present blocked. The pressure differential normally createdby resistance 50 when there is flow through 5| no longer exists.Consequently, full pump pressure will be build up in line 52 reacting onescape valve 54 against the pressure of spring 55, tending to move thisvalve to the right, opening up communication between line 42 andreservoir connection 56, and thence through resistance 51 whichmaintains a prescribed back pressure into the reservoir 40.

At the same time, compressed air or other fluid actuating medium issupplied from source 68 to valve casing 6| by way of cannelure 82 ofvalve 83 and conduit 64 to the rear of left hand pressure port 85 of thechuck control mechanism, where it is introduced by channel 88 to therear of piston 81. Piston 61 has its rod 88 terminating in a he d 68engaging the clamp devices 18, which due to their angular position inthe work chuck head H are drawn together, interiorly disengagingthemselves from the work piece.

With the parts in the position just described, as handle 38 isoscillated in a counterclockwise direction, rock arm 12 .which isfrictionally secured to move with shaft 82 by the opposed clutch membersl8 and 14, urged toward each other by spring 15, will be oscillated alsoin a counterclockwise direction or with its lower portion, as viewed inFigure 5, moving toward the right. This arm has adjustably secured to itas by the bolt a second section 11 carrying the cross pin 18, engaged inthe elongated notches l8 and 88 of the valve members 53 and 8|respectively.

It is to be noted that valve member 83 is actuated downwardly, as viewedin Figure 4or correspondingly, to the right as viewed in Figure 3 by thetension spring 82. Consequently, as pin 11 is shifted by oscillation ofarm 12, the spring will cause immediate follow-up of valve 88, while dueto the elongation of the notch 88 the position of valve 8| which isurged upwardly as viewed in Figure 4, or to the left as viewed in Figure3, by the compression spring 83 will remain unchanged.

When the parts have reached their first phase of movement, as indicatedin Figure 6, valve -88 under the influence of its spring will thereforehave been completely shifted, coupling pressure source 68 with conduit84 extending to the right hand side of piston 61 causing a retractingmovement of head 59 and arms 18, clamping work piece IS in position onthe work head or chuck l5.

Continued movement of lever 33 will then cause reaction of pin 18against valve 8|, shifting this valve against force of spring 83. Thisshifting of valve 8| will then couple pressure line 44 through cannelure85 with conduit 21 leading to the upper portion of cylinder 26, therebyraising the cylinder rapidly to cause a rapid traverse or infeed of thegrinding wheel with respect to the work piece now firmly held on androtating with the work head. Continued movement of handle 33 in aclockwise direction effects a continuing advance of cam 3| which isrigidly secured on the shaft. Due, however, to the fact that the valvemembers 63 and 8| have both already been shifted to a maximum extent inthe direction of movement of pin I8, no further movement of the pin andvalves is possible. Consequently, arm 12 remains stationary, its hubslipping between the clutch members 18 and 14 of shaft 32.

It is to be noted that cam 3| has a very slight or gradual rise and canbe moved through an arc of some 40 degrees for effecting desired slowfeeding movement of the grinding wheel until the work is reduced toproper size. An adjustable stop 34 is preferably provided on the bed Hito engage lever 33 and positively limit its movement and this movementof the cam in the feeding direction so that the operator can readilybring the handle up to this stop and know that the work has been groundto the prescribed size.

The actual work size is visibly indicated to the operator by the gage 85whose hydraulic motor 38 is coupled with the conduits 64 and 84 so thatthe gage is automatically swung into and out of effective positionsimultaneously with the clamping and unclamping of the work piece. Anyslight size variance can therefore be compensated by adjustment of thework head as an entirety through the medium of lead screw |8 and pilotwheel 20.

The grinding having been completed, handle 88 is moved in a clockwisedirection, initially eflect ing a slight movement of cam 3|, permittingthe wheel to retract slightly with respect to the work piece andeffecting discontinuance of the grinding operation. Continued movementof the handle carries with it lever 11 and pin 18, releasing retainingpressure on valve 8| which is then urged outwardly by its spring 83reversing the pressure and exhaust connections to motor 26. The conduitconnections then existing, as respects the valve 8|, are thus shown inFigure 3.

With the parts thus adjusted, line 21 is connected through'valve 8|,conduit 85 and resistance 51, maintaining a pressure condition in thesystem to reservoir. The weight of the grinding head 22 is such as tobear against the piston, tending to force out the fluid at the upperportion thereof, the piston movement being further effected byintroduction of pressure into the lower portion of cylinder 24 from line28. This effects an immediate rapid retraction of the grinding wheel.Continued movement of lever 33 then positively, reversely shifts valve63, introducing air or other fluid pressure into cylinder 38 forretraction of the gage as respects the work and simultaneously by thesame pressure coupling moves piston 61, moving the chuck fingers 10 intowork receiving position. It is to be noted that all of these movementstake place during the initial clockwise movement of lever 33. Thismovement brings the terminii of the two valve members against theadjustable stops 86 and 81, preventing further movement of the valves,and

' thus of rock arm 11, which, therefore, slips in a reverse direction onshaft 32 during the further movement of the lever necessary to returncam 3| to starting position.

As indicated by the several dotted line positions in Figure 3, thecyclic relation of the parts is preferably such that in initiatinggrinding action, a first 7 degrees movement of lever 33 operates theclamp cylinder for securing the work piece in position, andsimultaneously therewith moves the visual or other gage device intocontact with the work; the succeeding 7 degrees movement effects therapid hydraulic infeed which has been shown as effective as respects thegrinding wheel head, although it is to be understood that it is equallyapplicable to movement of the work head as an entirety under a similarpiston control mechanism, if preferred. Continned movement of lever 33directly efiects the slow or relative feeding movement of grinding wheeland work as through the medium of the rise on cam 3|, to any desiredextent, an arc of movement of not over 40 degrees having so far beenfound entirely suitable.

As the extended movement of valves 63 and 8| are a direct function ofthe oscillation of rock arm 11, it will be apparent that on reversemovement of the parts from the grinding position, shown in Figure '7, tothe initial position shown in Figures 3 and 4, valves 63 and 8| will beoperated in reverse order but in accordance with similar increments ofmovement of shaft 32 and lever 33, the first operation being a slightseparation of work and grinding wheel by initial reversal of cam 3|followed up by a movement of valve 8| under influence of its spring,causing rapid relative separation of work and grinding Wheel, andthereafter a retraction of the gage and release of the work piece sothat it may be withdrawn with one hand by the operator, while thecontinued retraction of the feed cam 3| is being effected by his otherhand. In this manher a sure and rapidclamping of the work, and advanceof the work to grinding position is effected with a subsequentcontrolled feeding action, while on reversal of the parts appreciabletime saving in production is effected byinitiating the retraction andrelease of the work immediately upon reversal of lever 33, in place ofthe cycle, necessitating first a slow retraction corresponding to theinitial feed, and then subsequent rapid retraction and work release atthe end of the reverse movement of the feed control elements.

What is claimed is:

1. In a hydraulically operable machine tool having means for clampingthe work and means for effect ng relative approach and retraction of thework and tool, said means including hydraulic camp ng and feedingmechanisms, a supplemental feed mechanism, control valves for saidhydraulic mechanisms, and means for effecting shifting of said valves ininverse order during the initial approach and initial retraction of workand tool, including a reversely actuable control device having-partsmovable therewith reacting on said valves for determining the sequentialshifting of said valves.

2. In a hydraulically operable machine tool having means for clampingthe work and means for effecting relative approach and retraction of thework and tool, said means including hydraulic clamping and feedingmechanisms, a supplemental feed mechanism, control valves for saidhydraulic mechanisms, and means for effecting shifting of said valves ininverse order during the initial approach and initial retraction of workand tool, including a reversely actuable control device having partsmovable therewith reacting on said -valves for determining thesequential shifting of said valves, said control device including amanual actuator and means shiftable in accordance with movement of saidactuator for controlling the supplemental feed mechanism.

3. A machine of the character described including tool and work supportsrelatively movable toward and from each other, work clamping mechanismcarried by the work support, hydraulic actuators for effecting the workclamping and said relative movement of the parts, control valvestherefor, an oscillatable control member, a positive feed determinatorshiftable thereby, and an impositive control for the valve membersmovable with and relative to said oscillatable control.

4. A machine of the character described including tool and work supportsrelatively movable toward and from each other, work clamping mechanismcarried by the work support, hydraulic actuators for effecting the workclamping and said relative movement of the parts, control valvestherefor, an oscillatable control member, a positive feed determinatorshiftable thereby, an impositive control for the valve members movablewith and relative to said oscillatable control, and a friction slipcoupling for effecting the impositive connection between the valve anfeed controls.

5. A control mechanism for a grinding machine of the character describedembodying a work support having a work clamping member, a tool support,and means for mounting said work and tool supports for relative approachand retraction, said control mechanism including a primary device foreffecting rapid approach and retraction of said parts, and a fine feeddevice having a progressive follow-up action as respects the primarydevice, hydraulic mechanisms for actuation of the work clamp and saidprimary device, sequentially operable control valves for said hydraulicmechanisms, and an oscillatable control member for said valves and feeddevice, having means for effecting the actuation of said valves ininverse order at the initiation of each change in direction ofoscillation thereof, whereby said hydraulic mechanisms are in eachinstance rendered effective prior to the operative effect of the feedmechanism.

6. The combination with a grinding machine including a bed or support,an oscillatable wheel head mounted thereon and means for effectingoscillation of the head in a direction toward and from a work pieceincluding a hydraulically shiftable plunger and a cam member forco-acting with the plunger, of control mechanism for shifting of thewheel head including an oscillatable shaft supporting the cam, means foroscillating the shaft, a rock arm carried by the shaft, a slip couplingbetween the arm and shaft permitting overrunning of the shaft withrespect to movement of the arm, and a control valve for the hydraulicplunger actuable by the arm on initial oscillation of the shaft ineither direction, whereby the hydraulic plunger anticipates the reactionof the cam on the wheel head.

7. A control mechanism for a grinding machine of the characterdescribed, which embodies a work head having a work clamp mechanism anda grinding wheel disposed in opposition to the work head for movementinto an operative relation with respect thereto, said control mechanismincluding a manually oscillatable shaft, a rock arm carried by the shaftfor movement therewith and relative thereto, a friction coupling betweenthe arm and shaft whereby the arm will be actuated by the shaft oninitial movement thereof in either direction, work clamping and rapidtraverse mechanisms operable by the arm in reverse directions uponinitial actuation of the shaft, and a feed determinator carried by theshaft and effective throughout an appreciable arc of oscillationthereof, whereby the feed determinator supplements the action of therock arm control mechanism in either direction of oscillation of theshaft, substantially as and for the purpose described.

8. In a machine of the character described, the combination with a bedor support and a carriage mounted thereon for movement relative thereto,of means for effecting a controlled relative movement of said parts,including a hydraulically actuable plunger member carried by one of saidparts and an oscillatable cam carried by the other of said parts wherebyoscillation of the cam will effect a direct mechanical shifting of theplunger, a source of hydraulic pressure, and a control member fordetermining the coupling of the hydraulic medium to the plunger foreffecting shifting of the plunger with respect to its associated member,and connections between the cam and control member for actuating same toreverse the effect of the hydraulic actuating medium on the plunger atthe inception of each oscillatory movement of the cam.

9. In a machine of the character described including tool and worksupports relatively movable toward and from each other, work clampingmechanism carried by the work support, hy-

a,147,ees

draulic actuators for effecting the work clamping and said relativemovement of the parts, control valves therefor, an oscillatable controlmember, a mechanical feed determining cam operable by said controlmember, and an impositive control for the valve members movable with andrelative to said feed control cam.

10. In a machine of the character described including tool and worksupports relatively movable toward and from each other, work clampingmechanism carried by the work support, hydraulic actuators for effectingthe work clamping and said relative movement of the parts, controlvalves therefor, an oscillatable control member, a mechanical feeddetermining cam operable by said control member, an impositive controlfor the valve members movable with and relative to said feed controlcam, and connections between said cam and the hydraulic actuator foreffecting relative movement of the parts, whereby during movement of thetool and work supports relatively toward each other, said cam will beadditively eflective as respects the hydraulic actuator in producingsaid movement.

11. A machine of the character described including tool and worksupports relatively movable toward and from each other, work clampingmechanism carried by the work support, a rapid traverse mechanism foreffecting rapid relative movement of the tool and work supports, asupplemental oscillatable control member for determining relativefeeding movement of the supports. a source of hydraulic actuatingmedium, and means for determining the effect of the hydraulic medium onthe work clamping and rapid traverse mechanisms including a pair ofoppositely biased resiliently actuated valve members and a jointactuator coupled with the oscillatable control member and having a lostmotion connection with both of said valve members, whereby said valvemembers will be shifted in a given direction in inverse order uponactuation of the control member.

12. A grinding machine including a bed or support, a wheelhead mountedthereon, a work support adapted to present a work piece in opposition tothe wheelhead, hydraulically actuable means for clamping the work pieceon the work head, and means for hydraulically determining movement ofthe wheelhead in a direction toward and from the work support, a sourceof hydraulic medium for actuation of said clamping andhead moving means,and means for controlling the coupling of the hydraulic medium with saidparts for eflecting predetermined cyclic operations thereof, including apair of Juxtapositioned valve elements, resilient means oppositelyurging said valve elements, means for limiting the movement of saidvalve elements in either direction, and an oscillatable actuator havinglost motion connection with both of said valve elements, whereby ineither direction of. movement of the oscillatabie control element, oneof said valves will be resiliently urged with the control element toanticipate the movement of the other valve by the amount of, said lostmotion and the cyclic effect of the valves will be in inverse order asrespects opposite directions of oscillation of the control member.

FREDERICK S. HAAS.

